Anthony Albanese and Richard Marles will be the only contenders for Labor's new federal leadership team, barring any late shocks on Monday.
No other challengers have put their names forward to replace Bill Shorten and Tanya Plibersek, with nominations closing on Monday. Caucus will meet on Thursday.
Both men have promised to talk to voters who didn't vote Labor in a bid to make sure they understand last Saturday's shock election loss.
"It's really important that we understand what happened at the election. It's important we make sure we're talking to the widest range of people we can," Mr Marles told reporters in Melbourne on Sunday.
Mr Albanese has also promised to talk to voters outside the Canberra and Labor bubbles in a bid to convince them his party can better represent them.
Labor has had a man and woman in the leadership team since 2001, except for a three-month stint in 2013 after Kevin Rudd got his revenge on Australia's first woman prime minister Julia Gillard.
But Victorian MP Clare O'Neil dropped out of the race for deputy after her colleagues told her she needed more experience bringing the party together behind a leader.
"Richard Marles has got the skills and the qualities and the experience at this stage to be able to do that job really well," Ms O'Neil told the ABC's Insiders.
Mr Marles said it was important to maintain the party unity that Bill Shorten instilled in Labor after the tumultuous Rudd-Gillard years.
"Certainly I hope I can be a force for unity in the party," he said.
Ms O'Neil did have a crack at Labor's "much too crowded" collection of policies.
"We took a big, unwieldy, risky policy agenda to the election and it was hard to explain and it was hard to defend and very easy to weaponise," Ms O'Neil said.
Labor's entire front bench also faces a shake-up following last weekend's unexpected federal election loss.
Australian Associated Press